This patch implements builtins for the following prototypes:

vector signed int vec_splati (const signed int);

vector float vec_splati (const float);

vector double vec_splatid (const float);

vector signed int vec_splati_ins (vector signed int, const unsigned int, const signed int);

vector unsigned int vec_splati_ins (vector unsigned int, const unsigned int, const unsigned int);

vector float vec_splati_ins (vector float, const unsigned int, const float);